Flotation device for amphibious vehicles



'Feb. 15, 1955 N. P. s. STRAUSSLER 2,702,017

FLOTATION DEiICE FOR AMPHIBIOUS VEHICLES Filed Oct. 10, 1952 I171) 81275211 111? S. Sing/Lesa 'lE v 2,702,017 Ice Patented Feb. 15, 19.55

2,702,017 FLQTATION DEVICE FOR- ANIPHIBIOUS VEHICLES Nic'liolas'Peter Son-ell Straussler, London, England Application October 10', 1952, Serial No. 314,119

4 Claims. (Cl. 114- This invention relates to collapsible hulls for amphibious motor driven vehicles of the kind wherein a hull comprises a continuous wall or' skirt of impervious flexible material secured by its lower margin to the body or to decking extending outwardly from the vehicle body to provide a watertight enclosure to afford buoyancy to the vehicle when afloat, means being provided for extending the wall or skirt and maintaining it in extended position.

The primary object of the present invention is to provide improved means for erecting the wall or skirt and holding it in erect position.

According to the broadest aspect of the present invention there are two continuous stiffening frames one secured to the upper margin of the wall or skirt and the other secured thereto intermediate the upper frame and the lower margin of the skirt. To this intermediate frame a number of intermediate members of collapsible struts are pivoted, the struts being preferably in the form of tubes and the axesofthe pivots horizontal and intermediate the ends of the members at right angles to the longitudinal axis of the frame. The length of said intermediate members, which can freely swing about their pivotal axes, is half or substantially so the height of the wall or skirt when erected. At each end of the aforementioned strut member a shorter strut member is pivoted. The length of each of these shorter or end strut members is substantially a quarter the height of the hull when erected. The outer ends of one of these shorter struts is pivoted to the upper frame, and the outer end of the other shorter strut is similarly pivoted to a bracket or lug on the body or the outer margin of the decking. The axes of the pivots just referred to lie in a vertical plane when the hull is erect or collapsed, but when the hull has been erected the pivotal axis between the intermediate and end struts are one on either side of the said plane so that some pressure has to be used to move the three members into and out of alignment.

Pneumatic, hydraulic, electrical or mechanical means may be provided for the operation of the struts, and for the erection of the wall or skirt. It is only necessary to raise the intermediate frame member in order to raise the entire screen, since the pivotal movement of the intermediate strut member will cause the simultaneous upward movement of the upper frame. The raising of the intermediate frame member may be effected by a number of air-proof fabric inflatable envelopes, one end of each of which is fixed on to the base decking and the other to the halfway frame. The admission of compressed air to inflate these envelopes will raise the intermediate frame; this movement automatically aligns the strut members and thereby raises the upper frame and the wall or skirt.

The collapsing of the skirt is performed by operating means to actuate valves to open position escape or exhaust of the compressed air from the envelopes and means for actuating the struts so that the elements move to positions permitting their collapse. The latter may be performed by a fluid pressure operated piston or plunger each of which acts on the lower short members of each strut to move the latter sideways and so permits each strut to fall into collapsed position, this position being in the form of a very low Z form. Other means may be employed in breaking the struts. The struts may be located inside or outside the skirt.

Means may also be provided whereby if one or more plungers fails to operate it is ensured that all the struts are actuated whereby they all fall to collapsed position simultaneously.

Referring now to the accompanying drawings:

Figure 1 is a side elevation of an amphibious military tank with the invention applied thereto;

Figure 2 is a plan view of Figure 1;

Figure 3 is" a part sideelevation on a larger scale;

Figure 3a is a fragmentary elevation viewed from the other side of the superstructure to that of Figure Figure- 4 is a similar view to Figure 3 showing a part- 15 collapsed position of the hull Structure; and

Figure 5 is a partial plan view showing a modification.

In the drawings, 1 is metal deck plating which surrounds and is secured to the body of the tank in aWtitertight manner and is located a short distance above the endless tracks 2. A collapsible hull is shown as 3 and comprises a skirt of waterproof flexible fabric, for example rubberised fabric, united by its lower margin in a waterproof manner to the outer margin of the decking 3. The enclosure may be made of a single length of the material having its end margins secured together in overlapping relation in a water-tight manner. The hull also comprises upper and lower stiffening frames 4, 5 of metal preferably of steel tubing, the frame 4 having the upper margin of the fabric surrounding it and secured thereto as by rubber adhesive, and the frame 5 which is located midway of the height of the skirt and on the inner side thereof, also has the fabric secured thereto as by rubber adhesive.

Surrounding the exterior of the skirt there are provided a series of vcollapsible struts. Each strut comprises three members 6, 7, 8 preferably of tubular steel, the end members 6 and 8 being respectively pivoted at their outer ends at 9a and 10 to the upper frame and lugs secured to the decking. The other ends of the members 6 and 7 are respectively pivoted at '11 and 12 to the upper and lower ends of the member 7. The member 7 is pivoted intermediate its ends at 9 to the frame 5. The pivots 11 and 12 are however, when the strut is erect, arranged one on either side of a plane containing the axes of the pivots 9, 9a and 10, this being provided for by laterally offset apertured lugs 13 at the adjacent ends of the members 6, 7 and 8, and it will be seen from Figure 3 that when the collapsible strut is erect the adjacent end faces 14, 15 of the members 6, 7 and 8 are in abutting relation.

Means for erecting the skirt comprises inflatable envelopes 16 within the skirt sealed at their upper ends and secured thereby at 17 to the frame 5. The lower end of each envelope is secured in an airtight manner to a base piece 18 secured to the decking and having a nonreturn inlet valve (not shown) through which air under pressure can be supplied from a pipe 19 to inflate the envelope. The pipe 19 is connected to all the base pieces so that the envelopes will be inflated simultaneously. Each base piece 18 also has an exhaust valve (not shown) all of which are opened simultaneously by manual operation of an endless cable 20 for deflating the envelopes.

Reverting to the struts, means is provided for simultaneously actuating them when the hull is to be collapsed. For this purpose lugs 21 project upwardly from and are secured to the decking outside the skirt. Each lug has secured thereto a single acting compressed air cylinder 22 in which is slidably mounted a piston 23 having a piston rod 24. The outer end of the piston rod 24 in each case is normally spaced laterally from the lower member 8 of the adjacent strut and each cylinder has means for connecting its outer end to a compressed air pipe line for supplying compressed air simultaneously to all the cylinders whereby the pistons are moved to the right (Figure 3) and engage the lower members 8 of the struts and then move them to the position as shown in Figure 4, whereupon provided the exhaust valves of the envelopes are open the struts and frames will descend under the action of gravity and collapse the skirt. In order to control the collapse of the structure the said exhaust valves may be such as to provide for slow escape of the compressed air from the envelopes.

In order to ensure that all the struts are actuated in the event that one or more of the pistons 23 fail to -lowered positions.

operate, each piston rod has an integral projection 25 secured at its outer portion to a flexible endless cable 26 trained round grooved pulleys 27 rotatably mounted on the decking. As an alternative to the pulleys a bell- -crank lever 28 may be pivoted'to the decking adjacent same time all the struts will be actuated so that the .upper frame member 4 will be moved upwardly relatively to the lower frame member until the envelopes have been inflated to such an extent that the frames are near their upper positions. The struts can each then be moved to their final positions manually or by suitbale means so that the members 6, 7 and 8 of each strut rare in vertical alignment, Figure 4, with the faces 14, 15

in abutting engagement. The fabric of the hull will thus be tautened and the hull as a whole will be held in extended position by the struts, it being understood that if desired the air under pressure may be then exhausted from the envelopes, as the structure will then be solely supported by the struts.

When it is desired to collapse the hull air under pressure is supplied to the cylinders 22, whereupon the pistons 23 are moved to the inner ends of the cylinder so that the strut members are moved by the piston rods v24 out of alignment (Figure 4).

I claim:

1. A flotation device for imparting buoyancy to an amphibious vehicle comprising a continuous collapsible hull of flexible impervious material extending about the vehicle body and secured by its lower margin in a waterproof manner thereto, continuous upper and lower stiffening frames the former being secured to the upper margin of the hull and the latter to the hull inter- 4 mediate the upper and lower margins thereof and a plurality of foldable struts'which when erected support the hull in extended position, each of which struts consists of an intermediate member pivoted intermediate its ends to the lower frame, an upper member and a lower member respectively pivoted at their outer ends to the upper frame and to the vehicle body, and at their inner ends to the ends of the intermediate member for movement about axes which are located one on either side of the axis of the strut when the latter is in erected position, abutments carried by said members which are in engagement when the strut is in erected position and means operable for simultaneously moving the struts to their erected positions whereby the frames are raised and the hull is extended.

2. A flotation device as claimed in claim 1, wherein said means comprises a plurality of impervious inflatable envelopes each of which is secured at its upper end to said lower frame and at its lower end to a base fixed to decking secured to the vehicle body each base is provided with a non-return inlet valve, whereby the envelopes can be inflated simultaneously by air under pressure from a supply pipe.

3. A flotation device as claimed in claim 2, wherein each base has a normally closed exhaust valve and means is provided for opening the exhaust valves simultaneously for deflation of the envelopes.

4. A flotation device as claimed in claim 3, having fluid pressure operated means for simultaneously acting on the lower members of the struts for initially moving them to positions whereby thereafter the struts and the hull will move under the action of gravity to their collapsed positions.

References Cited in the file of this patent UNITED STATES PATENTS 494,823 Pitt Apr. 4, 1893 1,311,429 Weir July 29, 1919 1,462,422 Rinesi July 17, 1923 2,390,747 Straussler Dec. 11, 1945 

